Lubricating oil composition, inhibitor therefor, and method of manufacturing the same



' give acceptable service.

- Patented Au 19, 1941 LUBRICATING OIL COMPOSITION, INHIB- ITOR THEREFOR, AND METHOD OF MAN- UFACTURING THE SAME Troy Lee Cantrell and James Otho Turner, Lansdowne, Pa., assignors to Gulf Oil Corporation, Pittsburgh, Pa., a corporation of Pennsylvania No Drawing. Application September 15, 1936, Serial No. 100,956

12 Claims.

Our invention relates to lubricating oils and more particularly to lubricating oil compositions containing an oil-soluble agent or agents efiective to inhibit or mitigate the normal corrosive or destructive action of lubricating oil deterioration products upon certain types of bearing me ils under certain conditions of use, said agent or "agents also having the properties of impart1g so-called "extreme-pressure characteristics to the lubricating oil compositions, and also being effective to reduce or eliminate undesirable oxidation changes in the oil.

Despite the many technological advances made in the art of refiningand applying lubricating oils and in the composition of bearing materials,

- modern lubricating oils and bearings often fail to perform satisfactorily. It is well known in the art that straight petroleum lubricants have fairly well defined limits of bearing speeds, pres-- sures, and temperatures within which they will These limitations are often exceeded inmodern designs, resulting in machines that cannot be satisfactorily lubricated by straight mineral oils. These modern designs are justified, by engineers in their efforts to provide machines to conform to the ever-increasing demand for compactness, speed, power, and acceleration in modern engines. Many modern designs have already exceeded the abovementioned limits wherein straight petroleum.

lubricating oils' perform acceptably; therefore, it is necessary to provide lubricating compositions that extend and widen the limits formerly associated with straight lubricating oils.

Moreover, highly parafiinic oils having excellent viscosity-gravity constants, volatilities,

carbon residue values, and resistance to sludging and oxidation, and hence of high value for use vunder relatively mild lubricating conditions,

-high temperatures and pressures, and in the presence of certain metals. However, the inhibiting value of the nonparafiinic constituents is low per unit concentration, and they are less satisfactory with respect to viscosity-gravity constant, carbon residue, and similar criteria of lubricating quality than the paraflinic constituents. A more satisfactory solution of the problem would be to substitute for the nonparafiinic constituents removed in the more drastic refining treatments or absent because of the highly parafllnic nature of the original stock, some inhibiting or mitigating agent which would be far more effective per unit concentration and hence less detrimental with respect to the other physical properties which also effect the ultimate lubricating value of the oil.

Improved bearing metals have recently been" developed which are mechanically advantageous under many operating conditions. These bearing metals include binary'and ternary alloys of cadmium, silver, copper, lead, and nickel; as examples of such improved bearing metals frequently employed at the present time we may mention cadmium-silver, cadmium-silver-copper, cadmium-nickel-copper, and copper-lead alloys. However, such alloys are more subject to chemical attack than babbitt and other bearing alloys used in the past, and their use at high temperatures, high speeds, and high pressures is sometimes accompanied by a deterioration of the oils employed for their lubrication, which in turn may destroy the bearings. The exact mechanism of this action is no doubt complicated and is perhaps not fully understood; it is quite possible that some of the metals present in the bearings tend to promote such deterioration, and that other metals present are subject to attack from the deterioration products. Whatever the cause or the mechanism, the result is that the combination of drastic lubricating conditions and alloy bearings of the general nature indicated frequently causes trouble; the bearings may be badly etched or corroded, and the quality of the oil may be rapidly deteriorated.

It has been observed in some cases that the more highly paraffinic oils are apt to cause more difficulty in this respect than less parafiinic oils. It is highly desirable, therefore, to provide means whereby the oils may be so improved as to give satisfactory operating results under the conditions noted, and this is especially true insofar as concerns the more highly parafiinic oils, which should and do command a premium in price,

Moreover, it is well known that all hydrocarbon oils are more or less subject to changes through oxidation resulting in undesirable deterioration acid formation, and increase in carbon residue, viscosity, sludging, and the like. Such oxidative changes may become more rapid or more farreaching in extent in the presence of metals such as those employed in modern bearings, for example those of the general class mentioned above.

In order to meet these problems and to provide more satisfactory lubrication under the conditions indicated, various improvement agents have been incorporated in hydrocarbon oils prior to their sale and use. Some of these are extremely effective but too expensive for general use. Others, while having satisfactory inhibiting or mitigating characteristics, are unsatisfactory for other reasons. A primary requisite of any such improvement agents is good oil-solubility under service and marketing conditions; moreover, since solubilities vary in different types of oils, the improvement agent should be capable of being added in the requisite amount to oils of different characters.

The improvement agent should also be highly efiective per unit concentration in the lubricating oil compositions; otherwise it would be necessary to add such an amount of the improvement agent as to substantially modify many of the desirable physical properties of the lubricating oil itself. The lubricating oils in which the improvement agents are incorporated have been carefully refined to meet exacting specifications, and if it is necessary to incorporate therein a relatively large amount of some agent differing in physical properties from the oil itself, the resulting composition may prove unsatisfactory for the very purposes for which the lubricating oil was prepared. In general, it is desirable that the improvement agent should be effective at concentrations not exceeding one or two per cent by weight of the lubricating oil, although somewhat higher concentrations may occasionally be J'ustified for special purposes.

It is therefore an object of our invention to provide an improvement agent or inhibitor for addition to hydrocarbon lubricating oils which agent shall be in the form of a compound or compounds containing sulfur, or containing both phosphorus and sulfur, and having a satisfactory inhibiting or mitigating effect upon the destructive action of lubricating oils on alloy bearing surfaces under actual conditions of use where such destructive action would otherwise take place.

It is also an object of our invention to provide an improvement agent or agents of the character indicated herein, having the property of imparting desirable extreme-pressure characteristics to hydrocarbon oils when incorporated therein.

Another object of our invention comprises the provision of an improvement agent or agents for addition to hydrocarbon oils, having desirable anti-oxidant and stabilizing properties, and effective to retard increase in viscosity, carbon residue, acidity, and sludging of both highly paraifinic and less highly parafiinic oils.

A further object of our invention is to provide improved lubricating compositions comprising hydrocarbon lubricating oils and certain improvement agents incorporated therein.

A still further object of our invention is to provide a method or methods of manufacturing improvement agents having desirable characteristics for addition to mineral oils.

Our invention has for further objects such additional operative advantages and improve- Troy Lee Cantrell, Serial No. 64,413, filed Febtain xylenols ruary 17, 1936, and Serial No. 99,488 filed September 4, 1936, now issued as Patent No. 2,149,759, of March 7, 1939, to which reference may be had for further details. The disclosures of the copending applications referred to constitute in effect a part of the disclosure of our present application, insofar as relates to the preparation of such anti-oxidant materials, which are used as starting materials-in preparing improvement agents in accordance with our present invention. Referring, for example, to the aforesaid co-pending application, Serial No. 99,488, there is disclosed a process for the manufacture of antioxidant wherein a phenol is mixed with from 1 to 10 per cent of sulfuric acid having strength of 60 to per cent, or even fuming sulfuric acid, and an olefin or mixture of olefins is passed, preferably in the vaporous or gaseous phase, through the liquid mixture until the phenol undergoing reaction has gained in weight from 100 to 200 per cent, or thereabouts, followed by washing the product so obtained with water and caustic soda solution, the concentration of which does not exceed 15 per cent. Various phenols may be employed, for example phenol (CcHsOH) itself, the three cresols (C6H4CH3OH) and cer- (CsH3(CH3) 2-OH) or crude cresylic acids also maybe employed. The phenolic starting material should be as free as possible from pyridine bases; such pyridine bases may be removed by conventional methods such as washing with acid, or by distillation. As olefinic material there may be employed individual olefins themselves, mixtures of olefins, or mixtures of olefinic and non-olefinic material. By way of example, the oleflnic starting material may be butylenes, amylenes, refinery gases containing normally gaseous olefins (ethylenes, butylene, propylene) in varying amounts, and cracked distillates or other relatively low-boiling hydrocarbon mixtures containing normally liquid olefins and in some instances also containing substantial amounts of distilled normally gaseous olefins.

When the reaction is conducted with the olefin in the gaseous phase, the product is relatively highly concentrated with respect to effective anti-oxidant material and may not require distillation or concentration for the purpose of isolating the latter. On the other hand, when the reaction is conducted with the olefinic material in liquid phase, and especially when the concentration of olefins in the starting material is comparatively low, the product may be relatively dilute with respect to the efiective anti-oxidant material, comprising for example a solution of such anti-oxidant in gasoline-like polymers or unreacted liquid hydrocarbons. In such case. the

anti-oxidantvmaterial I may be concentrated by 1 distillationor otherwise as set forth in the aboveamentioned co-pending applica io P in the process described herein.

The exact chemical andistructural nature of 1 the anti-oxidant materials, as thus prepared and employedas starting material in the manufacture got our improved addition-agents, :is largely ob- 'scure. .Althoughwe-have been able .tov identify a certain types of compounds in these. anti-oxidant ,lmaterialsit will'be realized that,especially since mmixturesof various phenols and mixtures of ,various olefins are frequently employed in' the manufacture of these anti-oxidants, the number oi, possible chemical :compounds is large and variedpIn general, they differ from the simple alkylated phenols in that they are insoluble in dilute caustic soda solution, and alscin that they are good anti-oxidants and gum-inhibitors,

whereas simple'alkylated phenolsare not; In general, also, the alkylations, in such instances as they occur, are of secondary and tertiary types; the methods set forth in the above co-pending applications do not" produce normal or primary alkylation linkages. Alkylated phenols with normal or primary linkages are undesirable, due to the fact that both such materials and their products of reaction with sulfur chloride or'mlxt'ures of sulfur chloride and phosphorus trichloride tend to be relatively insolublein Pugh-gravity lubricating oils. phenols of normal or primary. linkage'might be 1: satisfactory provided the chains were long ,enough, say chains of four carbon atomsor more, .on account of the closer resemblance in structure .It is possible that certain alkylated of such compounds to paraflinic lubricatingoil constituents. However,-this is doubtful and such compounds would 'be expected to be of prohibitive cost. g 1' a g ,We have identified as constituents in the V various-anti-oxidant materials prepared'asset forth hereinbefore such compounds asfollows:

Orthodsopropyl phenol I r Ortho-tertiary butyl phenol I I 2,4-ditertiary butyl phenol Ortho-isoamyl phenol Ortho-teriary amyl phenol In addition to the above-listed compounds, -similar derivatives of various homologues of mono-, di-, and ,poly-hydroxy phenolsmay be present, a It may be remarked. however, that while some of the constituents of such ,antivoxidants may be identified, it is difiicult or impossible. to identify all of the constituents of any one anti-oxidant. material of the character interial'sfor the manu acture' of sulfur-containin improveme 8 1 inhibitors i afcqrdvance with our present invention; certainpfthe "conwstitu'ents of'th'e anti-oxidant starting material touse j aoxidants are nevertheless capable or *being' "con- *-verted by reaction with sulfur chloride or aihix- .tureof sulfur chloride and phosphorus trichloride to sulfur-containingmaterials useful asinhibitors.

-.aforesaid.' we prepare our improved additiorr agents or inhibitors 'by' reacting anti-oxidants" of: the general character described herein with sulfur chloride alone or with a mixture of sulfur chloride and" phosphorus trichloride.- We may also treatone batch of anti-oxidant material I with $2012 and another batch with P013 and blend the products." In' this case, however, the results are not necessarily identical withfthose prepared by using a mixture of SzClz and PCli, because of thepossibllity of interreaction between the latter, prior to and during the 'reactionwith the anti- 'oxidanta For example, the following reaction may take place at a temperatureof' 160 F.. or higher: 3PClq+S2Clr PCl5+2PSC1aQ The 'PCls and PSCla resulting from this reaction, if it occurs, will in turnjreact'with the anti-oxidant:

the products of the latter reaction are obviously not the same compounds as those resulting from individual and separate reactionswith SzCla and PCla,'respectively, but they are also effective and 1 useful for the purposes to which ourinvention is I addressed.

The general procedure is as follows: The anti- 1 oxidant material, which preferably shouldrbe dry,

is mixed either at atmospheric temperature or at ride or a'mixture of sulfur chloride and'phosa slightly elevated temperature with sulfur chlophorus trichloride, the mixture being stirred as the reaction proceeds. The temperature is then raised to 300 F., or thereabouts, and maintained at this elevated temperature for a suitable timein order to drive oft hydrogen chloride resulting from the. reaction. The product is then cooledand maybe used as such, although 'it is nearly always desirable to decolorize it, tosome extent at least. Thus the product may be cooled to around 250 F., and treated at that temperature' with a suitable solid absorbent material such as fullers earth, charcoal, acid-treated clay or the like. Alternatively the inhibitor, after cooling to. atmospheric temperature, maybe diluted with a suitable hydrocarbon liquid of lower viscosity in preparation for the filtration step. By way of example, we may employ a light naphtha as a diluent; the use of naphtha has the advantage that such naphtha maybe removed after the decolorizingoperation' by distillation.- Or we'may employ as diluenta lowviscosity lubricating oil similar to the oil to which the inhibitor is eventually-to be added; in such case it is unnecessa'ry to remove the'diluent prior toincorporating the inhibitor in the lubricating Theamount of reagent added will" vary over aconsiderable range, depending upon the desired characteristics ofvthe final'product and the'de- ,gree of, l concentration of the anti-oxidant. Whe re -the -anti-oxidantjstarting material is relatively highly concentrated and the reagent or reagents are added in sufficient amount to react rally, with all .of,the anti-oxidant; present, the

V productste'ndt'o be for high viscosity. With sulfur; chloride alone 'we'have prepared products containing asimuch es o, per cent byjweig ht .of sulfur, and fairly 'efiective materials containing as little asl per cent by weight ofIsulfur. However,

wefflnd that the'best resultseare obtainedcby limg h unt Q i J I c j o de 'jd dlto gi "products containing from about 5 to'7 per cent ,awhlch are not in themselves effective antiof sulfur, assuming the anti-oxidant starting material to be free or relatively free from diluent. Products containing sulfur within this preferred range are effective enough to be economical, and their physical properties such as solubility in oil, viscosity, and color make them highly suitable as addition agents, especially for incorporation in highly paraffinic oils. Moreover, by limiting the amount of sulfur chloride added to a point short of completion of reaction with all of the antioxidant, we obtain final products comprising mixtures of the sulfur-containing inhibitor and some of the original anti-oxidant material and having exceptionally advantageous properties. The unreacted anti-oxidant serves as a blending agent and also contributes anti-oxidant and stabilizing properties so that the products thus prepared are very soluble in highly parafflnic oils and while effective as inhibitors also have high antioxidant and stabilizing value, and are themselves stable to an advantageous extent.

In employing a mixture of sulfur chloride and phosphorus trichloride, or in blending the products separately prepared by reacting sulfur chloride and phosphorus trichloride, respectively, with anti-oxidant material of the character indicated, the total amount of combined sulfur and phosphorus should not exceed about ten per cent by weight of the final product. The preferred products are those which contain from 1.0 to 3.0 per cent of phosphorus and from 1.0 to 5.0 per cent of sulfur. As in the case of reaction with sulfur chloride alone, advantageous results may be secured by limiting the amounts of sulfur chloride and phosphorus trichloride to a point short of completion of the reaction with all of the anti-oxidant present.

We prefer to employ as starting materials antioxidants, prepared as set forth above and in the aforesaid co-pending applications. and having physical properties within the following range:

Gravity, API 15.0 to 25.0 Specific gravity; 60/60 F 0.9659 to 0.9042 Viscosity, SUV at 100 F 150 to (solid) Color Water white to 7 (NPA) Pour point (liquids only) F to 30 Melting point (solids only) F 80 to 225 Our invention, in its broadest aspects, however, is not limited to the preferred starting material mentioned hereinabove but contemplates the manufacture of inhibitors of the general class described from any alkylated phenols so long as such alkylated phenols possess definite anti-oxidant properties, are insoluble in water, insoluble or only slightly soluble in dilute alkali, and are permanently soluble up to per cent in paraffin oils. For example, we may employ as starting materials anti-oxidants prepared by reacting various light cracked hydrocarbon distillates and other normally liquid oleflnic mixtures with phenol, as described in the aforesaid co-pending applications. It is a requisite of such olefinphenol reaction products, however, insofar as the present process is concerned, that compounds contained therein shall contain. one or more secondary or tertiary carbon linkages or both.

The anti-oxidant value of this starting material should be such that the addition of 0.01 per cent by weight thereof to standard gasoline stock having an oxygen stability test (E. G. C. method) 01', say, minutes, will raise the oxygen stability to at least 240 minutes. Less potent anti-oxidants are unsuitable as starting materials.

The character of the final sulfur-containing inhibitor will, of course, vary with the character of the phenolic and olefinic material employed in the manufacture of the anti-oxidant starting material, with the extent of absorption of the olefin, and with the amount of sulfur, or phosphorus and sulfur, subsequently introduced. All of these factors are very intimately inter-related. These are the primary factors, but it will be obvious that there are numerous secondary factors, for example the degree of purification and decolorization of the anti-oxidant starting material.

Naturally, it is to be expected that the viscosities, specific gravities and other physical characteristics of the particular phenol employed will have a corresponding effect upon the prodnot, to some extent at least; this effect may, however, not always hold true where the degree of olefin absorption varies over comparatively wide limits and where the percentage of sulfur, or of phosphorus and sulfur, in the final compound also varies.

When cresylic acid, ortho-cresol and metacresol and the like are used in the manufacture of the anti-oxidant, we prefer to limit the olefin absorption to around one mol per mol of the .phenolic material, 1. e., to give a water-insoluble product representing roughly to per cent by volume of the original phenol, in order ultimately to secure inhibitors that are sufficiently soluble in the higher gravity oils.

When the anti-oxidant starting material is prepared from phenol (CsHsOI-I) itself, e. g., 90 per cent phenol, the degree of absorption of olefin may be carried farther, for example to about two mols of olefin per mol of phenol (based on the assumption that the olefin is made up entirely of C4 hydrocarbons).

The preferred olefins are those containing from three to eight carbon atoms per molecule; the higher the molecular weight of the olefin, the more viscous the final product will be. Olefins containing more than eight carbon atoms per molecule tend to reduce the sulfur content of the final inhibitor product. Ethylene (CzH4) on the other hand, is insufficiently reactive, requiring the use of fuming sulfuric acid, and does not sufficiently reduce the activity of the original phenol.

The best olefin starting materials are those containing from three to five carbon atoms per molecule, especially butylenes; fractions obtained from gases produced in the pyrolysis of hydrocarbon oils and rich in olefins of this approximate range represent advantageous and available raw materials.

After the reaction between the phenol and olefin has been carried to the desired degree of completion, the product is washed with water and dilute caustic soda in the manner set forth hereinabove and in the aforesaid co-pending applications. The resultant water-insoluble antioxidant material is then preferably dried. The drying may be accomplished by filtering the material through absorbent clay or the like, the effect of which is to dehydrate and decolorize. Or, the drying may be accomplished by heating the anti-oxidant material to about 400 F. in suitable apparatus; this procedure dehydratcs tilling over at vapor temperatures between 300' over between 300 and 550 F., which fraction V may then be treated with sulfur chloride, or a mixture of sulfur chloride and phosphorus trichloride. The lower boiling material, and sometimes also the residue, may be recycled for further reaction with olefins in the presence of sulfuric acid, or used as an anti-oxidant.

The following examples will serve to illustrate our invention in some of its more speciflcembodiments.

EXAMPLE 1 Preparation of anti-oxidant starting material 20 gals. of "90 per cent phenol were mixed with 5 per cent by weight of 94.5% sulphuric acid (C. P.). Olefin gas composed primarily of C4 hydrocarbons was then introduced into close "contact with the phenol-acid mixture until the volume of the reacting mixture increased to about 45 gals. This product was washed with gals. of caustic soda and later with 10 gals. of water. After neutralization the recovered product amounted to about 40 gals. Typiin this manner are as follows:

(b) Preparation of final inhibitor To 88 parts by weight of the anti-oxidant material prepared as described above, and preferably dry, 12 parts by weight of sulfur chloride were slowly added, the temperature meanwhile being raised-to about 300 F. and held at that temperature until evolution of hydrogen chloride ceased. The reaction product was then cooled to about 250 F., and was decolorized by contact with acid-treated clay. The resulting product had the following properties:

API

Gravity, 12.4 Viscosity, SUV at 100 F., seconds 1635 Color, NPA 6 Sulfur, percent by weight 6. 35

This product is a viscous, oil-like material resembling dark motor oil in appearance. (It will be obvious that the color of the material prepared in this manner will vary with the extent of decolorization'.) It is a highly suitable improvement agent or inhibitor for incorporation in.

hydrocarbon oil in proportions varying from 0.25 to 1.0, or more, per cent by weight.

EXAMPLE 2 (a) Preparation of anti-oxidant starting material Anti-oxidant material prepared as described in cal properties of anti-oxidant material prepared connection with Example 1(a), was distilled under vacuum of 11 to 12 in. Hg. The distillate was cut into three fractions. That fraction disand. 550 F., had the following properties:

Gravity, API 16.8 Viscosity, SUV at F., sec Color, NPA -13 (b) Preparation of final inhibitor 82 parts by weight of an anti-oxidant fraction prepared as described above were treated with 18 parts by weight of an approximately 25:75 mixture of sulfur chloride and phosphorus trichloride, the operating procedure being that described in connection with Example 1. The resulting material had the following properties:

Gravity, API 10. 6

Viscosity, SUV at 100 F., sec 731 Color, N 1.25 Phosphorus, percent by weight 2. 10 Sulfur, percent by weight 1. 88

This product is much less viscous than that prepared in accordance with Example 1, and represents an extremely effective improvement agent or inhibitor for addition to hydrocarbon oils in amounts up to from 1 to 2 per cent by weight of the oil.

These inhibitors, when added to hydrocarbon oils, strongly inhibit corrosion of metal alloy bearings such as those of silver, cadmium, copper and nickel, under conditions where the oil alone would cause such corrosion; oil compositions containing them also exhibit marked extremepressure characteristics. These inhibitors are stable at ordinary temperatures and do not tend to deposit out of lubricating oil compositions containing them on metal surfaces such as those of tin plate, terne plate or the like when packaged and stored prior to sale and use. They are permanently soluble in hydrocarbon oils of high paraflinicity. Moreover, these inhibitors have excellent anti-oxidant properties, the antioxidant properties rising in proportion to the amount of unreacted anti-oxidant starting material remaining in the final product. They are not subject to hydrolysis to any detrimental extent; the products of such hydrolysis as may occur are in themselves anti-oxidant and .non-

chloride and phosphorus tr-ichloride, inaccordance with the final concentration and proportions of sulfur and phosphorus desired in the final product. This regulation makes it possible to secure inhibitors having desired temperature responsiveness, activity, solubility, viscosity', .and

color, varying closely over a wide range.

An advantage of our process and product resides in the fact that the principal ingredients employed in the manufacture ofthe finalproduct, .1 namely oleflns, are cheap and available to the refiner. l

The following tables will serve to illustrate the effectiveness of our inhibitors and the value of lubricating compositions containing them.

Table I Oil cginrtaliiiiting one u or Untreated 011 (prepared as in Example 1) Make-up, percent by wt.:

Lubricating oil 100 99. 5 Inhibitor 0. 5 General properties:

Gravity, API 32. 5 32.4 Specific gravity, 60/60 F 0.8268 Viscosity, SUV- 100 F 183. 6 183. 5 210 F 46. 46. 2 Viscosity indcx 107.0 108.0 V G constant 0.804 0. 804 Flash, 00 F- 410 400 Fire, 00: F 470 465 Four point, "F" 0 Color, 1. 5 1. 75 Sulfur, B: percent. 0. 04 0. Carbon residue, percent 0. 04 0.03 Almen test:

Lover load, lb 10 16 Rubbing speed, i't./min 40 40. Unit load, lb./sq. in 5000 8000 Lubricant temp., F.

Initial 83 92 Final 100 148 Srzecial oxidation and corrosion Time oxidized, hr 48 48 Oil bath temperature, F. 347 347 Air rate, cc. per hr 2000 2100 Quantity of oil, cc 300 300 Oxidized oil- Gravity, API 30. 9 31. 6 Viscosity, SUV- 100 F 225. 2 191.0 210 F 48. 5 46. 6 Viscosity index 102.0 101. 0 Carbon residue, percent. 0. 61 0. Neutralization No 1. 82 0. 30 Cadmium-silver hearing- Weight before test, g 37. 1883 36. 0566 Weight after test, g 36. 4931 36. 0658 Change in weight -0. 6952 0092 Appearance Etched Good Table II firiiii one r Untreated oil (prepared as in Example 2) Makeup, percent by weight:

Lubricating oil 100. 0 99.0 Inhibitor l. 0 General properties:

Gravity, API 32.6 32. 3 Specific gravity, 60/60 F 0. 8628 0. 8644 Lb./Gal., 60 F 7. 184 7. 198 Viscosity, SUV- l00 F 186.0 186.0 210 F 46. 1 46.0 Viscosity index. 104 102 V-G Constant.-. 0.804 0.806 Flash, 00: F 410 405 Fire, 00: F 465 475 Pour point, F 0 0 Color, NPA 1. 5 1. 5 Sulfur B: percent. 0.04 0. 06 Phosphorus, percent. 0. 02 Carbon residue, percent 0.05 0. 06 Special oxidation and corrosion Time oxidized, hr 48 48 Oil bath temperature, 347 347 Air rate, cc. per hr.. 2000 2000 Quantity of oil, cc 300 300 Oxidized oil- Gravity, API 31. 2 32.3 Viscosity, SUV- 100 F 210 191 210 F 47 46 Viscosity index 95 97 Carbon residuei percenhn 0. 36 0. 18 Neutralization o 1. 33 0. 58 Cadmium-silver bearing- Weight before test, g 37. 2149 36. 8846 Weight after test, g. 36. 9665 36.8870 Change in weight, g -0. 2484 +0. 0034 Appearance Etched Good The lubricating oil used in the tests given in the tables given hereinabove was an SAE 10 1y controlled oil bath to C. (347 F.), and

air, at the rate of 2000 cc. per hour, is bubbled through the oil in contact with the bearing shell. At the end of 48 and 96 hours, the loss of weight and the condition of the bearing shell are determined, the bearing shell being washed free of oil and dried before weighing. When determining the efiectiveness of various improvement agents, the usual procedure is to run a "blank test simultaneously with the oil composition being tested, employing for that purpose a sample of the untreated oil. V

In this test it is advantageous to employ commercial bearing shells. These shells comprise a suitable metal backing faced, with the alloy bearing metal. In this way, the actual bearing face is subjected to severe deterioration conditions. By comparison of the results of such tests with actual service tests, we have found them to be in substantial agreement as to the suitability of particular lubricants.

In the tests given in the foregoing tables we employ so-called "cadmium-silver" bearings of the following approximate composition:

tremely high when expressed as per cent loss." is nevertheless very significant, as the bearing shells used have an alloy facing of only 0.008 to 0.012 in. thickness on a highly resistant backing and the observed losses in the reported tests often represent a loss of the order of 10 per cent of the alloy racing.

Various modifications in the operating procedure mentioned hereinabove will suggest themselves to those skilled in the art. For example, we have described washing the phenol-olefin reaction product with water and dilute caustic soda solution to eflect neutralization and removal of the acid or acids (e. g. sulfuric acid and sulfonic acids) remaining the reaction mixture after the introduction of the olefins has been discontinued. Such neutralization and removal may be effected in other ways, as by extraction with aqueous alcohol, contact with solid alkalis such as lime or sodium carbonate, or by contacting the reaction mixture with solid adsorbents such as fuller's earth, activated carbon, or the like.

Wherever the expression highly paramnic oil" is employed herein and in the claims hereinafter made it is in general intended to indicate lubricating oils conforming in physical properties to oils prepared from Pennsylvania crudes; these highly paramnic oils" are either oils derived from Pennsylvania crudes or oils which have been refined or blended to approach or even exceed the latter oils in parafllnicity. Where var-' ious materials are referred to as being soluble in such parafllnic oils, this expression is intended to mean that such materials may be incorporated into such oils in amounts up to 10 per cent, withever, commercial grades of this compound may contain varying quantities of other chlorides of sulfur such as $012, SaCh, S014, and S3Cl2. We may employ as the sulfur-containing reagent any of these sulfur chlorides, or mixtures of any two or more of the same.

While we have described our invention hereinabove with reference to various preferred forms and embodiments, and with reference to various specific examples, it will be understood that our invention is not limited to the details of such illustrative embodiments or examples but may be scope of the claims hereinafter made. More- 'over, while we have in certain instances specifically given certain preferred ranges and proportions, it will be understood that our invention is not limited thereto and that such preferred ranges and proportions are in general selected for particular products and particular purposes; variations in proportions and in the methods of preparation result in products of different charaoteristics, such products having individual advantages and utilities.

What we claim is:

1. The method of preparing an oil-soluble organic sulfur compound suitable as an improvement agent for hydrocarbon oils, which comprises reacting a sulfur chloride with a water-insoluble reaction product of a phenol and an olefin having anti-oxidant properties when added to a hydrocarbon oil, the reaction being carried to such extent as to incorporate sufilcient sulfur into the final product to give the final product the property of inhibiting the corrosion of bearing metals by hydrocarbon oil, when added to such oil, while retaining to a substantial extent the anti-oxidant value of the aforesaid phenololefin reaction product.

2. The method of preparing an oil-soluble organic sulfur compound suitable as an improvement agent for hydrocarbon oils, which comprises passing a gaseous olefin into contact with a .phenol in the presence of sulfuric acid until the'reacting mixture has increased in volume from to 250 per cent on the original phenol,

neutralizing the resultant anti-oxidant product,

and reacting at least a portion of the neutralized water-insoluble anti-oxidant product with a sulfur chloride to obtain a final oil-soluble material containing not more than about '7 per cent of sulfur.

3.,The method of preparing an oil-soluble organic sulfur compound suitable as an improvement agent for hydrocarbon oils, which comprises passing a gaseous olefin into contact with a phenol in the presence of a catalyst until. the phenol has absorbed from one to two mols of olefin per mol of phenol, washing the resultant anti-oxidant product with water and dilute alkali, and reacting at least a portion of the washed anti-oxidant product with a sulfur chloride.

4. An improvement agent for hydrocarbon lubricating oils comprising a sulfur-chloride reaction product of an alkylated phenol, said variously practiced and embodied within the alkylated phenol being a reaction product of an olefin and a phenol and a compound within the class consisting of secondary and tertiary alkylated phenols insoluble in water and in dilute alkali solution.

5. A method of lubricating bearing surfaces which comprises maintaining between bearing surfaces. one of which is an alloy of the class consisting of binary and ternary alloys of cadmium, silver, nickel, copper and lead, a film of lubricating oil which initially produces an effective lubricating action but which would normally tend to corrode the aforesaid alloy, and maintaining the effectiveness of the lubricating oil by incorporating therein a sulfur-chloride treated waterinsoluble secondary or tertiary alkylated phenol in a small but sufiicient proportion substantially to reduce the corrosion.

6. The method of preparing oil-soluble organic compounds suitable as improvement agents for highly parafiinic lubricating oils which comprises reacting an olefin and aphenol in the presence of a catalyst, washing the resultant product with water and dilute alkali, treating at least a portion of the product with a sulfur chloride, and regulating the degree of absorption of olefin in the initial reaction stage with reference to the specific chemical character of the phenol and olefin, to secure an intermediate water-insoluble product which, when treated in the subsequent reaction stage with the sulfur chloride in the required amount to introduce from one to seven per cent of sulfur into the aforesaid intermediate product, will yield a sulfur-containing product soluble in highly paraffinic oil.

'7. The method of preparing an oil-soluble organic compound suitable as an improvement agent for highly parafiinic lubricating oils, which comprises reacting an olefin and a phenol in the presence of a catalyst, washing the resultant product with water and dilute alkali, treating a portion of the product with sulfur chloride and treating a second portion with phosphorus trichloride, and blending the resultant products to obtain a final product soluble in highly parafiinic oil, and containing a total of not more than about 10 per cent of combined sulfur and phosphorus.

8. The method of preparing an oil-soluble organic compound suitable as an improvement agent for hydrocarbon oils, which comprises reacting an olefin and a phenol in the presence of sulfuric acid, and treating at least'a portion of the resultant product with a mixture of sulfur chloride and phosphorus trichloride.

9. The method of preparing an oil-soluble organic compound suitable as an improvement agent for hydrocarbon oils, which comprises reacting an olefin and a phenol in the presence of sulfuric acid, and treating at least a portion of the resultant product with a mixture of sulfur chloride and phosphorus trichloride to obtain a final inhibitor product containing a total of from about 2 to 10 per cent of combined sulfur and phosphorus.

10. The method of preparing an oil-soluble organic compound suitable as an improvement agent for hydrocarbon oils, which comprises reacting a mixture of sulfur monochloride and phosphorus trichloride with a water-insoluble reaction product of a phenol and an olefin, said reaction product having anti-oxidant properties when added to a hydrocarbon oil.

11. The method of preparing an oil-soluble of inhibiting corrosion of bearing metals by hydrocarbon oil, when added to such oil, while retaining to a substantial extent the anti-oxidant value of the aforesaid phenol-olefin reaction products.

12. A lubricating composition comprising a major amount of a hydrocarbon lubricating oil and a minor amount of a sulfur-chloride reaction product of an alkylated phenol, said alkylated phenol being a reaction product of an olefin and a phenol and a compound within the class consisting of secondary and tertiary alkylated phenols insoluble in water and in dilute alkali solution.

TROY LEE CANTRELL. JAMES OTHO TURNER. 

